1. Field of the Invention
The present invention relates to a recording tape cartridge which rotatably accommodates a single reel onto which a recording tape such as a magnetic tape or the like is wound.
2. Description of the Related Art
Recording tapes such as magnetic tapes and the like are used as external recording media for computers and the like. Because such recording tapes have large recording areas and are mainly employed for back-up of large volumes of information, it is desirable that the adherence of dust can be prevented and that accommodation space during storage is small.
Accordingly, recording tape cartridges in which a recording tape is wound on a single reel and rotatably accommodated in a case are employed. Thus, adherence of dust to the recording tape can be prevented by the case, and accommodation space during storage can be substantially halved in comparison with structures which are provided with a second reel around which the recording tape is wound during recording and/or replaying of information on the recording tape.
When recording of information to the recording tape and/or replay of information that has been recorded at the recording tape is to be carried out, the recording tape cartridge is loaded into a drive device, and the recording tape is sequentially drawn out from the case while being wound at a winding reel of the drive device. Hence, the recording tape is disposed along a predetermined tape path and recording and/or replay of the information is achieved by a recording/replaying head of the drive device.
Accordingly, at this recording tape cartridge, an opening aperture portion for drawing out the recording tape is provided in the case, and a leader member for drawing-out operation is provided at a distal end of the recording tape. Below, an example of such a recording tape cartridge is described on the basis of FIGS. 12A and 12B.
FIG. 12A shows a perspective view of a corner portion of a recording tape cartridge 100. FIG. 12B shows a sectional plan view of a corner portion of a case 102 which structures the recording tape cartridge 100. As shown in these drawings, an opening 104, which is formed by diagonally cutting away the corner portion, is formed in the case 102. A leader block-retaining portion (opening portion) 108, whose inner periphery is defined by a corner wall 106, is provided inward from the opening 104. The leader block-retaining portion 108 is defined from above and below by tongue portions 110 and 112, which are provided extending from a ceiling plate and floor plate, respectively, of the case 102.
A window portion (opening) 114, which communicates with the opening 104, is formed in the corner wall 106. A magnetic tape 118, which is a recording tape wound on a single reel 116 accommodated in the case 102, can be drawn out through the window portion 114 and opening 104. A leader block 120 is connected to a distal end of the magnetic tape 118. When the magnetic tape 118 is not in use, the leader block 120 is accommodated and retained at the leader block-retaining portion 108. When the magnetic tape 118 is to be used, the leader block 120 is operated by drawing-out means of the drive device, is taken out from the leader block-retaining portion 108, and is guided to the winding reel.
In the state in which the leader block 120 is accommodated at the leader block-retaining portion 108, the leader block 120 is in a state of abutting against the corner wall 106, and a rear corner portion 120A of the leader block 120 engages with a protrusion portion 124 formed at a free-standing end portion of a side wall 122 of the case 102. A front end portion 120B of the leader block 120 is engaged with a leaf spring portion 128 formed at a free-standing end portion of a front wall 126 of the case 102. In this state, the leader block 120 closes off the window portion 114.
When the leader block 120 is to be taken out from the leader block-retaining portion 108, the leader block 120 is rotated by the drawing-out means, in the direction of arrow C, around an engagement position of the rear corner portion 120A and the protrusion portion 124. Hence, the leader block 120 elastically deforms the leaf spring portion 128 engaging with the front end portion 120B in the direction of arrow D, passes through the opening 104, and is removed from the leader block-retaining portion 108. Further, the leader block 120 is accommodated and retained back in the leader block-retaining portion 108 by an opposite operation.
Thus, in this structure, removal of the leader block 120 from the leader block-retaining portion 108 is prevented simply by engaging the front end portion 120B and rear corner portion 120A of the leader block 120 with the protrusion portion 124 and leaf spring portion 128 of the case 102, and the leader block 120 is easily attached and detached at the leader block-retaining portion 108 by a small operational (rotating) force of the drawing-out means.
However, in the conventional recording tape cartridge 100 described above, there is a problem in that strength of a periphery around the opening 104 is low, because edge portions of the opening 104 are defined by respective free-standing end portions of the tongue portions 110 and 112, the side wall 122, and the front wall 126 (the leaf spring portion 128).
Consequently, if, for example, the recording tape cartridge 100 is dropped, peripheral edge portions of the opening 104 (the tongue portion 110, the leaf spring portion 128 and the like), which are provided at the corner portion of the case 102 and are susceptible to being impacted on a floor or the like, may be plastically deformed and/or damaged. This plastic deformation or damage is a cause of retention and mounting/removal of the leader block 120 at the leader block-retaining portion 108 inward from the opening 104 becoming impossible (making re-use impossible).
Moreover, even in cases which do not result in plastic deformation of peripheral edge portions of the opening 104, for example, if the leaf spring portion 128 is elastically deformed by a falling impact, misplacement or falling-out of the leader block 120 from the leader block-retaining portion 108 may occur, and dust and the like may adhere to the magnetic tape 118 as a result.
Furthermore, recording tape cartridges in which an opening provided in the side wall 122 or front wall 126 of the case 102 is opened/closed by a sliding door, hinge-type lid or the like are also known. However, edge portions of such openings are defined by respective free-standing end portions of the ceiling plate, floor plate and side wall or front wall of the case 102, and these recording tape cartridges have not caused an improvement in dropping strengths.